Applying protective coatings to optical fibers

ABSTRACT

Apparatus, systems, and methods that provide coats on a glass optical fiber including of an inner layer and an outer layer. The method includes two steps. First, a conductive polymer coating is applied to the optical fiber as it is being produced. Second, a protective coating is applied to that conductive polymer coating. The conductive polymer coating is applied immediately after the fiber is drawn from preform to fiber.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to and benefit under 35 U.S.C. § 119(e)of U.S. Provisional Patent Application No. 63/027,685 filed May 20, 2020entitled “applying metal coatings to optical fibers via a conductivepolymer coating followed by a metal coating,” the content of which ishereby incorporated by reference in its entirety for all purposes.

STATEMENT AS TO RIGHTS TO APPLICATIONS MADE UNDER FEDERALLY SPONSOREDRESEARCH AND DEVELOPMENT

This invention was made with Government support under Contract No.DE-AC52-07NA27344 awarded by the United States Department of Energy. TheGovernment has certain rights in the invention.

BACKGROUND Field of Endeavor

The present application relates to optical fibers and more particularlyapplying protective coatings to optical fibers including a conductivepolymer coating and another coating.

State of Technology

This section provides background information related to the presentdisclosure which is not necessarily prior art.

Scratches to optical fibers drastically reduce their mechanicalstrength, so optical fibers are encased in some form of protectivecoating to prevent scratching. These coatings are typically organicpolymers. These polymer coatings are typically applied in line duringfiber production, immediately after a glass preform is drawn into afiber. This is accomplished by pulling the fiber through a liquidmonomer solution, which adheres to the fiber and is then cured either byexposure to UV light or heat. While these coatings are robust in benignenvironments, they degrade at elevated temperatures and are unstable inmany corrosive environments. Furthermore, they are thermally insulating,which can lead to challenges in situations where control of fibertemperature by either active heating or cooling is important.

SUMMARY

Features and advantages of the disclosed apparatus, systems, and methodswill become apparent from the following description. Applicant isproviding this description, which includes drawings and examples ofspecific embodiments, to give a broad representation of the apparatus,systems, and methods. Various changes and modifications within thespirit and scope of the application will become apparent to thoseskilled in the art from this description and by practice of theapparatus, systems, and methods. The scope of the apparatus, systems,and methods is not intended to be limited to the particular formsdisclosed and the application covers all modifications, equivalents, andalternatives falling within the spirit and scope of the apparatus,systems, and methods as defined by the claims.

The inventor's apparatus, systems, and methods provide a multi-layercoating on a glass optical fiber consisting of an inner conductivepolymer layer and at least one outer protective layer. The inventor'sapparatus, systems, and methods have use by manufacturers of componentsfor fiber-interfaced packages and optical fiber fabricators.

In various embodiments the inventor's apparatus, systems, and methodsinclude two major steps. First, a conductive polymer coating is appliedto the optical fiber as it is being produced. Second, a protectivecoating is applied to that conductive polymer coating. In otherembodiments additional layers, including metal layers, are applied. Theconductive polymer coating is applied immediately after the fiber isdrawn from preform to fiber.

The apparatus, systems, and methods are susceptible to modifications andalternative forms. Specific embodiments are shown by way of example. Itis to be understood that the apparatus, systems, and methods are notlimited to the particular forms disclosed. The apparatus, systems, andmethods cover all modifications, equivalents, and alternatives fallingwithin the spirit and scope of the application as defined by the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated into and constitute apart of the specification, illustrate specific embodiments of theapparatus, systems, and methods and, together with the generaldescription given above, and the detailed description of the specificembodiments, serve to explain the principles of the apparatus, systems,and methods.

FIG. 1 illustrates one embodiment of the inventor's apparatus, systems,and methods.

FIG. 2 provides further details of the inventor's apparatus, systems,and methods 100 illustrated in FIG. 1.

FIG. 3 illustrates another embodiment of the inventor's apparatus,systems, and methods.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

Referring to the drawings, to the following detailed description, and toincorporated materials, detailed information about the apparatus,systems, and methods is provided including the description of specificembodiments. The detailed description serves to explain the principlesof the apparatus, systems, and methods. The apparatus, systems, andmethods are susceptible to modifications and alternative forms. Theapplication is not limited to the particular forms disclosed. Theapplication covers all modifications, equivalents, and alternativesfalling within the spirit and scope of the apparatus,

Referring to the drawings and in particular to FIG. 1, one embodiment ofthe inventor's apparatus, systems, and methods is illustrated. Thisembodiment is designated generally by the reference numeral 100. Theembodiment 100 includes the structural elements identified and describedbelow.

Reference numeral 102—Fiber with conductive polymer coating,

Reference numeral 104—Fiber,

Reference numeral 106—Furnace,

Reference numeral 108—Coating die,

Reference numeral 110—Liquid monomer/liquid suspension,

Reference numeral 112—Liquid monomer coated on fiber,

Reference numeral 114—Bank of UV lamps or Furnace, and

Reference numeral 116—Polymerized/consolidated coating.

The structural elements of the system 100 having been identified anddescribed the operation of the system 100 will now be considered. First,the starting preform glass (not shown) is drawn to a fiber 104 bypassing it through a furnace 106 under tension on a draw tower. Belowthe furnace 106 sits a coating die 108 filled with a liquid monomer 110.In an alternative embodiment the coating die 108 is filled with a liquidsuspension of the desired conductive polymer. The fiber 104 is drawnthrough this die 108, leaving a coating 112 of the liquid monomer (orsuspension) 110 on the fiber 102. The coating 112 is thenpolymerized/consolidated by passing it through a bank of UV lamps orfurnace 114, producing a continuous coating of conducting polymer 116.In another embodiment the coating 116 is polymerized/consolidated bypassing through a f a bank of UV lamps or furnace 114. This results in alength of optical fiber 102 coated with a protective coating 116.

FIG. 2 provides further details of the inventor's apparatus, systems,and methods 100 illustrated in FIG. 1. FIG. 2 is a schematic depictionillustrating further details of the inventor's apparatus, systems, andmethods 100. FIG. 2 includes the structural elements identified anddescribed below.

Reference numeral 202—Fiber,

Reference numeral 204—Metal salt,

Reference numeral 206—Aqueous solution,

Reference numeral 208—Electroplating chamber,

Reference numeral 210—Power supply,

Reference numeral 212—conductive polymer coating,

Reference numeral 214—Counter electrode (anode), and

Reference numeral 216—Metal coating.

The structural elements of the inventor's apparatus and, systems havingbeen identified and described, the operation of the inventor'sapparatus, systems, and methods will now be considered. A polymercoating 212 is applied to the fiber 202. An outer metal coating is thenapplied to the conductive polymer coating. This is accomplished using anelectroplating chamber 208. A metal salt 204 is dissolved in an aqueoussolution 206, and the fiber 202 is inserted into the solution 206. Thechoice of metal salt or multiple metal salts determines the compositionof the metal coating, and other electroplating parameters such assupporting electrolytes and additives determine the morphology of thecoating. The electroplating setup consists of a power supply 210, acounter electrode (anode) 214, and a voltage applied between the counterelectrode 214 and the polymer-coated fiber 202. The voltage causesreduction of the metal ions on the surface of the conductive polymercoating 212, plating a metal coating 216 on the outside of the fiber202. The voltage can be applied because the conductive polymer coating212 of the fiber 202 is sufficiently conductive to act as an electrodein the electroplating solution. An embodiment of the electroplated metal216 illustrated in FIG. 2 is copper. Another embodiment of theelectroplated metal 216 is gold. Yet another embodiment of theelectroplated metal 216 is silver. Still another embodiment of theelectroplated metal 216 is nickel. Another embodiment of theelectroplated metal 216 is tin. Another embodiment of the electroplatedmetal 216 is chromium. In various other embodiments the electroplatedmetal 216 is other metals and alloys. This plating step can be doneeither by submerging the entire fiber at once or by drawing the fiberthrough the plating solution, either in-line with the entire fabricationprocess or after the tower draw as a separate step. Electroplating is arelatively fast deposition process, with deposition rates on the orderof a micrometer per minute. Due to the metal coating thickness requiredfor the fiber 202, i.e., tens of micrometers, very short electroplatingtimes are required.

Referring to FIG. 3, another embodiment of the inventor's apparatus,systems, and methods is illustrated. This embodiment is designatedgenerally by the reference numeral 300. The embodiment 300 includes thestructural elements identified and described below.

Reference numeral 302—Preform glass,

Reference numeral 304—Furnace

Reference numeral 306—Uncoated Fiber

Reference numeral 308—Coating die filled with liquid monomer (additionalembodiment a polymer suspension)

Reference numeral 310—Coating of liquid monomer on the surface of thefiber

Reference numeral 312—Furnace or UV lamps

Reference numeral 314—Fiber coated with conducting polymer

Reference numeral 316—Electroplating chamber

Reference numeral 318—fiber pulling apparatus

Reference numeral 320—metal coated optical fiber

Reference numeral 322—spool of coated fiber

The structural elements of the embodiment of the inventor's apparatus,systems, and methods 300 having been identified and described theoperation of the embodiment 300 will now be considered. First, thestarting preform glass 302 is drawn to a fiber 306 by passing it througha furnace 304 under tension from a fiber pulling mechanism 318 in a drawtower. Below the furnace 304 sits a coating die 308 filled with a liquidmonomer. In another embodiment the coating die 308 is filled with aliquid suspension of the desired conductive polymer. The fiber 306 isdrawn through this die 308, leaving a coating 310 of the liquid monomer(or suspension) on the fiber 306. The coating 310 is thenpolymerized/consolidated by passing through a bank of UV lamps 312. Inanother embodiment the coating 310 is polymerized/consolidated bypassing through a furnace 312. This results in the optical fiber 302being coated with a conductive polymer protective coating 314. Thiscoated fiber then enters an electroplating chamber 316 similar to theone described in FIG. 2. In this chamber, the fiber is passed through ametal salt solution (not shown) and a metal coating is deposited on thefiber. The metal- and conductive polymer-coated fiber 320 is removedfrom the electroplating chamber and collected on a spool 322.

Although the description above contains many details and specifics,these should not be construed as limiting the scope of the applicationbut as merely providing illustrations of some of the presently preferredembodiments of the apparatus, systems, and methods. Otherimplementations, enhancements and variations can be made based on whatis described and illustrated in this patent document. The features ofthe embodiments described herein may be combined in all possiblecombinations of methods, apparatus, modules, systems, and computerprogram products. Certain features that are described in this patentdocument in the context of separate embodiments can also be implementedin combination in a single embodiment. Conversely, various features thatare described in the context of a single embodiment can also beimplemented in multiple embodiments separately or in any suitablesub-combination. Moreover, although features may be described above asacting in certain combinations and even initially claimed as such, oneor more features from a claimed combination can in some cases be excisedfrom the combination, and the claimed combination may be directed to asubcombination or variation of a subcombination. Similarly, whileoperations are depicted in the drawings in a particular order, thisshould not be understood as requiring that such operations be performedin the particular order shown or in sequential order, or that allillustrated operations be performed, to achieve desirable results.Moreover, the separation of various system components in the embodimentsdescribed above should not be understood as requiring such separation inall embodiments.

Therefore, it will be appreciated that the scope of the presentapplication fully encompasses other embodiments which may become obviousto those skilled in the art. In the claims, reference to an element inthe singular is not intended to mean “one and only one” unlessexplicitly so stated, but rather “one or more.” All structural andfunctional equivalents to the elements of the above-described preferredembodiment that are known to those of ordinary skill in the art areexpressly incorporated herein by reference and are intended to beencompassed by the present claims. Moreover, it is not necessary for adevice to address each and every problem sought to be solved by thepresent apparatus, systems, and methods, for it to be encompassed by thepresent claims. Furthermore, no element or component in the presentdisclosure is intended to be dedicated to the public regardless ofwhether the element or component is explicitly recited in the claims. Noclaim element herein is to be construed under the provisions of 35U.S.C. 112, sixth paragraph, unless the element is expressly recitedusing the phrase “means for.”

While the apparatus, systems, and methods may be susceptible to variousmodifications and alternative forms, specific embodiments have beenshown by way of example in the drawings and have been described indetail herein. However, it should be understood that the application isnot intended to be limited to the particular forms disclosed. Rather,the application is to cover all modifications, equivalents, andalternatives falling within the spirit and scope of the application asdefined by the following appended claims.

1. An apparatus for making an optical fiber, comprising: a startingpreform glass, a fiber draw tower for drawing said starting preformglass into a fiber, a coating die containing a liquid monomer, or aliquid suspension wherein said fiber is drawn through said coating dieleaving said liquid monomer or said liquid suspension as a coating onsaid fiber, and a bank of ultraviolet lamps or a furnace wherein saidfiber with said liquid monomer or said liquid suspension as a coating isdrawn into said ultraviolet lamps or said furnace and polymerized orconsolidated by said ultraviolet lamps or said furnace and results insaid fiber being coated with a conductive polymer protective coating, 2.The apparatus of claim 1, further comprising a chamber containing metalin a solution wherein said fiber coated with a conductive polymerprotective coating is drawn through said chamber resulting in said fibercoated with a conductive polymer protective coating being coated with ametal coating.
 3. The apparatus of claim 1, wherein said coating diecontains said liquid monomer.
 4. The apparatus of claim 1, wherein saidcoating die contains said liquid suspension.
 5. An apparatus for makingan optical fiber, comprising: a starting preform glass, a fiber drawtower for drawing said starting preform glass into a fiber, a coatingdie containing a liquid monomer, or a liquid suspension wherein saidfiber is drawn through said coating die leaving said liquid monomer orsaid liquid suspension as a coating on said fiber, a bank of ultravioletlamps or a furnace wherein said fiber with said liquid monomer or saidliquid suspension as a coating is drawn into said ultraviolet lamps orsaid furnace and polymerized or consolidated by said ultraviolet lampsor said furnace and results in said fiber being coated with a conductivepolymer protective coating, and an electroplating chamber containing ametal salt dissolved in an aqueous solution wherein said fiber coatedwith a conductive polymer protective coating is inserted into saidelectroplating chamber resulting in said fiber coated with a conductivepolymer protective coating being coated with a metal coating.
 6. Theapparatus of claim 5, wherein said coating die only contains said liquidmonomer.
 7. The apparatus of claim 5, wherein said coating die onlycontains said liquid suspension.
 8. The apparatus of claim 5, whereinsaid fiber with said liquid monomer or said liquid suspension as acoating is only drawn into said ultraviolet lamps.
 9. A method of makingan optical fiber, comprising the steps of: providing a starting preformglass, using a fiber draw tower for drawing said starting preform glassinto a fiber, drawing said fiber through a coating die containing aliquid monomer or a liquid suspension wherein said liquid monomer orsaid liquid suspension is left as a coating on said fiber, and drawingsaid fiber with a liquid monomer or liquid suspension as a coatingthrough a bank of ultraviolet lamps or a furnace wherein said fiber withsaid liquid monomer or said liquid suspension as a coating is drawn intosaid ultraviolet lamps or said furnace and polymerized or consolidatedby said ultraviolet lamps or said furnace and results in said fiberbeing coated with a conductive polymer protective coating.
 10. Themethod of claim 9 further comprising the step of inserting said fibercoated with a conductive polymer protective coating into a chambercontaining metal in a solution resulting in said fiber coated with aconductive polymer protective coating being coated with a metal coating.11. The method of claim 9, wherein said coating die only contains saidliquid monomer.
 12. The method of claim 9, wherein said coating die onlycontains said liquid suspension.
 13. The method of claim 9, wherein saidwherein said fiber with said liquid monomer or said liquid suspension asa coating is only drawn into said ultraviolet lamps.
 14. The method ofclaim 9, wherein said wherein said fiber with said liquid monomer orsaid liquid suspension as a coating is only drawn into said furnace. 15.The method of claim 9, wherein said wherein said fiber coated with aconductive polymer protective coating is inserted into said chamberresulting in said fiber coated with a conductive polymer protectivecoating being coated with a copper metal coating.
 16. The method ofclaim 9, wherein said wherein said fiber coated with a conductivepolymer protective coating is inserted into said chamber resulting insaid fiber coated with a conductive polymer protective coating beingcoated with a gold metal coating.
 17. The method of claim 9, whereinsaid wherein said fiber coated with a conductive polymer protectivecoating is inserted into said chamber resulting in said fiber coatedwith a conductive polymer protective coating being coated with a silvermetal coating.
 18. The method of claim 9, wherein said wherein saidfiber coated with a conductive polymer protective coating is insertedinto said chamber resulting in said fiber coated with a conductivepolymer protective coating being coated with a nickel metal coating. 19.The method of claim 9, wherein said wherein said fiber coated with aconductive polymer protective coating is inserted into said chamberresulting in said fiber coated with a conductive polymer protectivecoating being coated with a tin metal coating.
 20. The method of claim9, wherein said wherein said fiber coated with a conductive polymerprotective coating is inserted into said chamber resulting in said fibercoated with a conductive polymer protective coating being coated with achromium metal coating.